How do I clear browsing history upon closing in Safari. I have an iphone xr

You can’t close Safari, so that won’t work. When you leave Safari you can go to Settings/Safari and tap Clear History and Website Data. Also in Settings/Safari, you can tap Close Tabs and set it to one day.

Another option is to only use Private Browsing. This will clear Safari when you leave it. Open Safari, tap the overlapped squares in the lower right corner and tap Private in the lower left.